3611 results about "Amplitude modulation" patented technology

An electrosurgical system has an electrosurgical generator and a bipolar electrosurgical instrument, the generator being arranged to perform a treatment cycle in which radio frequency energy is delivered to the instrument as an amplitude-modulated radio frequency power signal in the form of a succession of pulses characterized by successive pulses of progressively increasing pulse width and progressively decreasing pulse amplitude. There are periods of at least 100 milliseconds between successive pulses, and the treatment cycle begins with a predetermined pulse mark-to-space ratio. Energy delivery between pulses is substantially zero. Each burst is of sufficiently high power to form vapor bubbles within tissue being treated and the time between successive pulses is sufficiently long to permit condensation of the vapor.

An electrosurgical system has an electrosurgical generator and a bipolar electrosurgical instrument, the generator being arranged to perform a treatment cycle in which radio frequency energy is delivered to the instrument as an amplitude-modulated radio frequency power signal in the form of a succession of pulses characterized by periods of a least 100 milliseconds between successive pulses and by a predetermined pulse mark-to-space ratio. Energy delivery between pulses is substantially zero and the mark-to-space ratio is typically 1:4 or less. Each burst is of sufficiently high power to form vapor bubbles within tissue being treated and the time between successive pulses is sufficiently long to permit condensation of the vapor. The treatment cycles may each include an initial period and a subsequent period, the pulse duty cycle being increased or energy being delivered continuously in the subsequent period in order that tissue coagulation can be achieved quickly despite increasing tissue impedance.

One embodiment includes a sputtering system that includes a vacuum chamber; a substrate transport system configured to transport a substrate through the vacuum chamber; a cathode for supporting a sputtering target, the cathode at least partially inside the vacuum chamber; and a power supply configured to supply power to the cathode and the power supply configured to output a modulated power signal. Depending upon the implementation, the power supply can be configured to output an amplitude-modulated power signal; a frequency-modulated power signal; a pulse-width power signal; a pulse-position power signal; a pulse-amplitude modulated power signal; or any other type of modulated power or energy signal.

The invention discloses a multi-dimensional encryption anti-counterfeiting printing technology based on binary signals. According to the anti-counterfeiting printing technology, two-dimensional encryption anti-counterfeiting information can be generated into binary modulation signals by encryption and channel coding, and the anti-counterfeiting information is orderly changed in an amplitude modulation screening form and embedded into a whole page in a modulation mode of a circulating table look-up method, so that the anti-counterfeiting information can be identified from a random fragment during presswork identification. The technology has strong fragment resistance, can resist illegal copying behaviors based on a camera, a scanner, an electronic document and the like more effectively, and can be widely applied in the anti-counterfeiting field of presswork.

The invention discloses an encrypting anti-counterfeiting printing technology for modulating the shapes of amplitude modulation dots of a printed work through a binary-system encrypting signal. In the anti-counterfeiting printing technology, anti-counterfeiting information is subjected to encryption and channel coding to form a binary-system modulating signal and the anti-counterfeiting information is embedded into a whole page by sequentially changing the shapes of the amplitude modulation dots in a circulating table lookup modulation way. During recognition of the printed work, the anti-counterfeiting information can be recognized from any fragment, so the anti-breakage performance is high, the illegal replication based on a camera, a scanner, an electronic document and the like can be more effectively prevented and the technology can be extensively applied to the field of printed work anti-counterfeiting.

One aspect of the present invention is related to a quantum cryptographic scheme comprising at least one sending unit including a physical means of encoding and distributing a raw key in the quadrature components of quantum coherent states that are continuously modulated in phase and amplitude, at least one receiving unit containing a physical means of performing homodyne detection of the quantum coherent states in order to measure the quadrature components of the states, a quantum channel for connecting the sending unit to the receiving unit, a two-way authenticated public channel for transmitting non-secret messages between the sending unit and the receiving unit, a quantum key distribution protocol ensuring that the information tapped by a potential eavesdropper can be estimated from the quantum channel parameters, and a direct or reverse reconciliation protocol that converts the raw continuous data into a common binary key.

An amplifier system is provided that switches between a linear mode of operation, an envelope tracking mode of operation and a polar mode of operation. The amplifier system switches between modes of operation based upon a characteristic of an input signal relative to a first threshold level and a second threshold level. A mode selector selects the operation mode by transmitting an amplitude modulated signal plus a variable headroom voltage to a supply terminal of a power amplifier during the envelope tracking mode, an amplitude modulated signal to the supply terminal and phase modulated input signal during the polar mode and a substantially constant amplitude signal to the supply terminal during the linear mode.

A holographic waveguide display comprises: a source of light; at least one switchable grating layer comprising a multiplicity of grating regions each switchable between a diffracting state and a non diffracting state; means for spatio-temporally modulating light from the source to provide image light comprising at least one beam deflector for scanning the light in at least one of two orthogonal directions and at least one modulator for amplitude modulating the light. A first scanned angular range of light is diffracted through a first area into a first field of view by a first set of grating regions, and through a second area into to the first field of view by a second set of grating regions. Each grating region of the first and second sets has a first grating function. The first and second areas lie within an exit pupil of the display.

A class of bandwidth reduction techniques are used develop a broad class of modulation types collectively called SSB-FM. These signals can be used to construct communication systems that provide bandwidth-normalized performance gains of 10 dB or more when compared to popular prior art modulation methods. An aspect of the invention involves mapping trellis paths in a complex signal space onto corresponding real-valued trellis signals with desirable spectral properties. The invention can be used map continuous phase modulated (CPM) signals onto simpler amplitude-modulated trellis signals having double the channel capacity of prior art CPM signals. Multi-amplitude signaling and frequency division multiplexing may also be incorporated to further accommodate more information per symbol.

An amplifier circuit includes a power amplifier biased for saturated mode operation, and a controllable current source to provide supply current to the power amplifier. The controllable current source effects desired amplitude modulation of the output signal from the power amplifier by modulating the supply current it provides responsive to an amplitude information signal. In one or more embodiments, the current source includes a circuit that is configured to adjust one or more transmitter operating parameters responsive to detecting changes in the effective DC resistance of the power amplifier. For example, the circuit may generate a compensation signal that reduces the effective DC resistance responsive to detecting that the effective DC resistance has undesirably increased. By way of non-limiting examples, such compensation may be effected by changing a current mirror, an amplifier-to-antenna impedance matching, an amplifier bias or device size, or imposing some form of transmit signal back-off.

A method is provided for an equalization strategy for compensating channel distortions in a dual-polarization optical transport system wherein the received signal includes a complex signal of a first transmitted polarization component and a complex signal of a second transmitted polarization component. In a first step, a blind self-recovery mode used a blind adaptation algorithm in calculating and modifying multiple complex equalizer transfer function coefficients to enable recovery of only the complex signal of the first transmitted polarization component. By recovering only a single polarization component in the first step the degenerate case of recovering only a single transmitted signal at both polarization component outputs of an equalizer is prevented. In a second step, equalization is performed in a training mode for calculating and modifying the multiple complex equalizer transfer function coefficients to enable recovery of the complex signals of the first and second transmitted polarization components. In a third step, equalization is performed in a data directed mode for continuing to calculate and modify the multiple complex equalizer transfer function coefficients to ensure continued recovery of the complex signals of the first and second transmitted polarization components. The method is suited for a digital signal processing implementation in a coherent receiver when a modulation scheme used on a transmitted signal is quadriphase-shift keying (QPSK). In other embodiments, the method can be used with modulation schemes such as binary PSK, M-ary PSK where M>4, or Quadrature Amplitude Modulation (QAM).

A fully automated package identification and measuring system, in which an omni-directional holographic scanning tunnel is used to read bar codes on packages entering the tunnel, while a package dimensioning subsystem is used to capture information about the package prior to entry into the tunnel. Mathematical models are created on a real-time basis for the geometry of the package and the position of the laser scanning beam used to read the bar code symbol thereon. The mathematical models are analyzed to determine if collected and queued package identification data is spatially and/or temporally correlated with package measurement data using vector-based ray-tracing methods, homogeneous transformations, and object-oriented decision logic so as to enable simultaneous tracking of multiple packages being transported through the scanning tunnel.

Apparatuses (e.g., devices, systems), and methods for transdermal electrical stimulation (TES). Apparatuses described herein can be self-contained, lightweight, and wearable. The apparatuses and methods described herein be configured to apply an ensemble current waveform between the two or more electrodes, wherein the ensemble current waveform comprises a series of component waveforms that are sequentially applied, and wherein each component waveform is different from a component waveform immediately before it and wherein transitions between the component waveforms temporally correlates with transitions in the sensory experience. Also described are neurostimulators for application of transdermal electrical stimulation (TES) and methods of using them for comfortably inducing a cognitive effect. Also described are Methods and apparatuses for amplitude modulation of all or a portion of an ensemble waveform to modify a user's cognitive state by transdermal electrical stimulation (TES).

A tape data carrier for protecting articles and documents from counterfeiting and copying is formed by a polymer structure including at least one polymer layer of which at least one layer has at least one of through-perforations and pits. These through-perforations and pits are preferably between 0.001 mum and 20 mum in size and can be filled with different materials. The data carriers can carry concealed and visible macro-and micro- images created by heavy-ion bombardment of the polymer film, subsequent exposure of the bombarded film to ultraviolet radiation, and etching of the polymer film in a solvent. A device for manufacturing a data carrier of this type includes the following elements configured in series: a heavy ion source; a heavy ion beam-formation system; an ion guide; a three-dimensional amplitude modulation unit; and a target which is destined to become the data carrier. The three-dimensional amplitude modulation unit is designed to hold a matrix of wafers and is connected to a drive for rotating and translating the wafers. The drive is connected via a control unit to the three-dimensional amplitude modulation unit for positioning the target.

The amplitude modulator comprises: an angle modulator for angle-modulating a phase signal to be inputted; a waveform shaping means in which, (1) when the magnitude of an amplitude signal to be inputted becomes smaller than a first prescribed value, a waveform of the amplitude signal is shaped so that the magnitude of the amplitude signal of the portion which becomes small becomes the first prescribed value; and/ or (2) the waveform shaping means in which, when the magnitude of the amplitude signal to be inputted becomes larger than the second prescribed value which is larger than the first prescribed value, the waveform of the amplitude signal is shaped so that the magnitude of the amplitude signal of the portion which becomes larger becomes the second prescribed value; and an amplitude modulator for amplitude modulating the signal of the output of the angle modulator by the signal of the output of the waveform shaping means.

An acoustic agglomerator for agglomerating constituents in a fluid is provided. The acoustic agglomerator includes an area containing a fluid having constituents and an acoustic generator operable to generate a modulated acoustic field to enhance agglomeration of the constituents in the fluid. In one aspect the acoustic field is frequency modulated and in other aspects the acoustic field is amplitude modulated, while yet in other aspects the acoustic field is both frequency and amplitude modulated. A method for agglomerating constituents in a fluid is also provided. The method includes providing a fluid with a constituent and applying an acoustic field to the fluid. The method provides for modulating the acoustic field to cause the constituent to agglomerate.